Methods and systems for in-process quality control during drill-fill assembly

ABSTRACT

A method for assembling a structure is described. The method includes locating a position in an assembly stack-up where a one-sided fastener is to be installed, drilling a hole through the assembly stack-up at the position, countersinking the hole to a specified depth, operating a calibrated probe to determine at least parameter associated with one or more of the hole and the stack-up proximate the hole, inserting the one-sided fastener into the hole, applying a rotational torque to the one-sided fastener to complete installation of the one-sided fastener, and comparing a measurement of angular displacement required to complete installation of the one-sided fastener to a range of angular displacement indicative of correct installation of the fastener.

BACKGROUND

The field of the disclosure relates generally to couplings made betweentwo or more mechanical components, and more specifically, to methods andsystems for in-process quality control during drill-fill assembly.

In the most relevant example, aerospace structure assembly generallyrequires multiple “touch” processes to complete installation offasteners and acquire quality assurance acceptance. These multipleprocesses require significant flow time and therefore are subject tolarge labor costs. In addition, the staging of such an assembly processusually results in a significant amount of work in process as anassembly line generally incorporates only one process at a location.Further, and as understood by contemplation of the below mentionedprocess, assembly mechanics in the labor force may be exposed torepetitive motion injuries.

For example and to illustrate, fabrication of a typical aerospaceassembly includes a first process to locate and drill the hole, a secondprocess to complete a countersink associated with the drilled hole, athird process to inspect the hole and countersink, a fourth process toinstall the fastener and a fifth to inspect and accept the installation.Thousands upon thousands of such fastener installations are used in atypical airframe. Added to the above, after the drilling andcountersinking steps are completed, an assembly may be disassembled forremoval of burrs associated with the drilling of the holes. As such theassembly must be reassembled so that the fasteners may be installed. Insummary, usual assembly requires temporary assembly, drilling,disassembly, reassembly and multiple inspection processes along the way.

There are efforts underway that address the disassembly of structuresfor the deburring of holes, for example, the use of interference fitfasteners that counteract the effects burrs have on the integrity of astructure. However, installation of fasteners, including blind-sidefasteners and one-side fasteners common to aerospace structurefabrication are still subject to manual inspection and validation byquality assurance personnel. Required access to such assemblies forinspection slows the fabrication process.

BRIEF DESCRIPTION

In one aspect, a method for assembling a structure is provided. Themethod includes locating a position in an assembly stack-up where aone-sided fastener is to be installed, drilling a hole through theassembly stack-up at the position, countersinking the hole to aspecified depth, operating a calibrated probe to determine at leastparameter associated with one or more of the hole and the stack-upproximate the hole, inserting the one-sided fastener into the hole,applying a rotational torque to the one-sided fastener to completeinstallation of the one-sided fastener, and comparing a measurement ofangular displacement required to complete installation of the one-sidedfastener to a range of angular displacement indicative of correctinstallation of the fastener.

In another aspect, a method for verifying correct one-sided fastenerinstallation is provided. The method includes rotating a bolt of theone-sided fastener until a torque required to rotate the bolt causes adrive head of the bolt to separate from the bolt, measuring a rotationof the bolt from a point where rotation of the bolt was initiated, to apoint where the drive head separates from the bolt, and comparing themeasured rotation to an expected rotation verify a correct installationof the fastener.

In still another aspect, a fastener insertion system is provided thatincludes a processing device and a rotation angle sensor communicativelycoupled to the processing device. The system is operable to rotate abolt of a one-sided fastener until a torque required to rotate the boltcauses a drive head of the bolt to separate from the bolt. Theprocessing device is programmed to receive measurements of the rotationof the bolt by the system, determine an angle of rotation at which thedrive head separated from the bolt, and compare the angle of rotation atwhich the drive head separated from the bolt to known values associatedwith the fastener.

The features, functions, and advantages that have been discussed can beachieved independently in various embodiments or may be combined in yetother embodiments further details of which can be seen with reference tothe following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram of an aircraft production and servicemethodology.

FIG. 2 is a block diagram of an aircraft.

FIG. 3 is an illustration of a one sided fastener inserted through ahole in an assembly.

FIG. 4 is an illustration of the bolt of FIG. 3, the drive head havingbeen rotated until a bulb has been formed in the nut body on theunderside of the assembly and the drive head broken away from theremainder of the bolt.

FIG. 5 is a diagram illustrating a numeric controlled drill-fill systemlocated to a drilling location where a front layer and a back layer ofan assembly are held in position with respect to one another.

FIG. 6 is a diagram illustrating the numeric controlled drill-fillsystem of FIG. 5 drilling a hole through the assembly.

FIG. 7 is a diagram illustrating the numeric controlled drill-fillsystem of FIG. 5 using a calibrated probe to check hole diameter, stackthickness, countersink depth, and the like in the assembly.

FIG. 8 illustrates a fastener feed head of the drill-fill system beingutilized to insert a fastener into the hole.

FIG. 9 shows that the drill-fill system inserts the fastener into thehole until an anti-rotation flange touches the front surface of theassembly.

FIG. 10 illustrates drill-fill system as having operated the fastener toform a bulb on a backside on the assembly via bolt rotation as well asthe breaking off of the drive head of the bolt.

FIG. 11 is a flowchart illustrating a method for assembling a structureutilizing the described embodiments.

FIG. 12 is a torque-angle plot of fastener installation.

FIG. 13 is a diagram of a data processing system that includes a torquesensor and a rotation angle sensor.

DETAILED DESCRIPTION

The described embodiments are directed to a one-sided fill-drill processusing a one-sided fastener. As further described herein, a hole isdrilled through a stack-up assembly, countersunk, and measurements aretaken of the countersink, the hole diameter and a thickness of thestack-up assembly. The fastener having the correct grip length is chosenbased on the thickness measurement and installed all in one step. When adrive head of the fastener is rotated for final installation, andultimately removed from the bolt through application of torque, suchtorque is monitored and correlated with torque data taken in testsand/or prior fastener installations to determine whether or not thefastener installation was performed correctly. As such, no postinstallation inspection related to the fastener is necessary.

In embodiments, an amount of rotation imparted onto the drive head untilit breaks free from the remainder of the bolt is measured. For a properfastener installation, a specific amount of rotation, within a range, isexpected. The measured rotation, for example in degrees, is measured andcompared to the expected range of rotation, for example as taken intests and/or prior fastener installations to determine whether or notthe fastener installation was performed correctly.

Referring more particularly to the drawings, embodiments of thedisclosure may be described in the context of aircraft manufacturing andservice method 100 as shown in FIG. 1 and an aircraft 200 as shown inFIG. 2. During pre-production, aircraft manufacturing and service method100 may include specification and design 102 of aircraft 200 andmaterial procurement 104.

During production, component and subassembly manufacturing 106 andsystem integration 108 of aircraft 200 takes place. Thereafter, aircraft200 may go through certification and delivery 110 in order to be placedin service 112. While in service by a customer, aircraft 200 isscheduled for routine maintenance and service 114 (which may alsoinclude modification, reconfiguration, refurbishment, and so on).

Each of the processes of aircraft manufacturing and service method 100may be performed or carried out by a system integrator, a third party,and/or an operator (e.g., a customer). For the purposes of thisdescription, a system integrator may include, without limitation, anynumber of aircraft manufacturers and major-system subcontractors; athird party may include, for example, without limitation, any number ofvenders, subcontractors, and suppliers; and an operator may be anairline, leasing company, military entity, service organization, and soon.

As shown in FIG. 2, aircraft 200 produced by aircraft manufacturing andservice method 100 may include airframe 202 with a plurality of systems204 and interior 206. Examples of systems 204 include one or more ofpropulsion system 208, electrical system 210, hydraulic system 212, andenvironmental system 214. Any number of other systems may be included inthis example. Although an aerospace example is shown, the principles ofthe disclosure may be applied to other industries, such as theautomotive industry.

Apparatus and methods embodied herein may be employed during any one ormore of the stages of aircraft manufacturing and service method 100. Forexample, without limitation, components or subassemblies correspondingto component and subassembly manufacturing 106 may be fabricated ormanufactured in a manner similar to components or subassemblies producedwhile aircraft 200 is in service.

Also, one or more apparatus embodiments, method embodiments, or acombination thereof may be utilized during component and subassemblymanufacturing 106 and system integration 108, for example, withoutlimitation, by substantially expediting assembly of or reducing the costof aircraft 200. Similarly, one or more of apparatus embodiments, methodembodiments, or a combination thereof may be utilized while aircraft 200is in service, for example, without limitation, to maintenance andservice 114 may be used during system integration 108 and/or maintenanceand service 114 to determine whether parts may be connected and/or matedto each other.

The description of the different advantageous embodiments has beenpresented for purposes of illustration and description, and is notintended to be exhaustive or limited to the embodiments in the formdisclosed. Many modifications and variations will be apparent to thoseof ordinary skill in the art. Further, different advantageousembodiments may provide different advantages as compared to otheradvantageous embodiments. The embodiment or embodiments selected arechosen and described in order to best explain the principles of theembodiments, the practical application, and to enable others of ordinaryskill in the art to understand the disclosure for various embodimentswith various modifications as are suited to the particular usecontemplated.

FIG. 3 is an illustration of a one-sided fastener 300 that has beeninserted into an assembly 310, shown in cut away view, made up of afront layer 312 and a back layer 314. The back layer 314 has a backside316 and the front layer 312 has a front side 318. Fastener 300 includesa nut body 320 and a core bolt 322. The core bolt 322 includes a lowerportion (not shown in FIG. 3) that extends through the nut body 320 anda frangible drive head 324. A portion of the nut body 320 is formed asan anti-rotation flange 330 with an anti-rotation recess pattern 332formed therein. Nut body 320 also includes a thread lock 334 forengaging threads (not shown in FIG. 3) of the core bolt 322. Fastener300 is shown in an “off-the-shelf” configuration. Upon completion of thehole drilling process through assembly 310, the fastener 300 is insertedinto the hole until the anti-rotation flange 330 is adjacent the frontside 318 of the front layer 312 as shown.

Fastener 300 is inserted into assembly 310 using an end effector module.A driver of the end effector module includes one or more protrudingtools that engage the anti-rotation recess pattern 332 to preventrotation of the nut body 320 during the final installation when thedriver of the end effector module engages the drive head 324 andinitiates rotation of the core bolt 322.

Now referring to FIG. 4, as the core bolt 322 is rotated, the threadlock 334 is caused to move up the threads 340 of the core bolt 322thereby causing a bulb 350 to be formed in a weakened portion of the nutbody 320, the bulb 350 being formed substantially adjacent the backside316 of the back layer 314. As is understood, upon formation, the bulb350 operates substantially in the same manner as a conventional nut withcore bolt 322 and the anti-rotation flange to hold the front layer 312and back layer 314 together.

Once the bulb 350 is properly formed, rotation of core bolt becomesincreasingly difficult until a specified torque range is achieved atwhich point the drive head 324 separates from a remainder 360 of thecore bolt 322 which is configured to be substantially flush with frontsurface 318 of assembly 310.

Turning now to FIGS. 5-11, the process for fabricating assembly 310 isfurther described. As mentioned above, fastener 300 (not shown in FIG.5) is utilized to provide an attachment between front layer 312 and backlayer 314. A numeric controlled drill-fill system 510 is utilized, whichlocates to a drilling location, for example using a vision system atleast partially located in end effector 520 to locate a reference point,such as a reference hole formed in assembly 310. In embodiments, drillfill system operates to press front layer 312 and back layer 314together and is programmed to move to a drilling location that isreferenced with respect to the reference point.

As shown in FIG. 6, drill-fill system 510 extends end effector module520 incorporating a drill bit 522 towards front layer 312 and back layer314 and commences to drill a hole 524 therethrough. Depending upon whichtype of fastener is to be utilized, drill-fill system 510 may beoperated to provide a countersink (as shown) such that upon completionof fastener 300 installation, fastener 300 and front surface 318 form aflush surface.

FIG. 7 illustrates that the drill bit 522 of drill-fill system 510 hasbeen removed from hole 324 and replaced with a calibrated probe 552.Calibrated probe 552 and drill-fill system 510 are automated and operateto check hole diameter, stack thickness, countersink depth, gaps and thelike between front layer 312 and back layer 314.

Once drill-fill system 510 has verified that the assembly 310 and thehole 524 extending therethrough meet specifications, a fastener feedhead 560 is utilized by drill-fill system 310 to insert a fastener 300into the hole 524, as shown in FIG. 8. In one embodiment, drill-fillsystem 510 selects the fasteners 300 based on the above describedthickness measurements such that the fastener 300 has a correct griplength for the assembly 310 in which it is being utilized. In certainembodiments, drill-fill system 510 verifies a length of the fastener300, and/or verifies that the fastener 300 incorporates the proper sizeand length of threads therein.

FIG. 9 shows that drill-fill system 510 inserts fastener 300 into hole524. The fastener 300 is inserted until anti-rotation flange 330 touchesthe front surface 318 of the assembly 310 and the nut body 320 extendsfrom the distal side. Fastener feed head 560 also operates as a driverand engages the anti-rotation flange 330 to prevent rotation of the nutbody 320 during the final installation when the driver engages the drivehead 324 and initiates rotation of the core bolt 322 until the bulb 350is formed and the drive head 324 breaks free as described above and asdepicted in FIG. 10.

FIG. 11 is a flowchart 600 illustrating the above described method forassembling a structure such as assembly 310. The method includeslocating 602 a position in an assembly stack-up where a one-sidedfastener (e.g., fastener 300) is to be installed, drilling 604 a holethrough the assembly stack-up at the position, countersinking 606 thehole 524 to a specified depth, operating 608 a calibrated probe 552 todetermine at least a thickness of the stack-up proximate the hole,inserting 610 the one-sided fastener into the hole, applying 612 atorque to the one-sided fastener to complete installation of theone-sided fastener, and comparing 614 a measurement of the torquerequired to complete the installation of the one-sided fastener to amonitored torque-angle curve (sometimes referred to as a torque rangecurve) to verify a correct installation of the fastener.

Additionally or alternatively, the method may include comparing ameasurement of angular displacement required to fracture the drive head324 from the core bolt 322 during installation of the one-sided fastener300 to a range of angular displacement indicative of correctinstallation of the fastener to verify a correct installation of thefastener.

In embodiments, locating 602 a position in an assembly stack-up includeslocating a reference on the assembly stack-up, and locating the positionfor the one-sided fastener installation with respect to the referencelocation. Further, insertion of the one-sided fastener 300 into the hole524 includes comprises selecting a one-sided fastener 300 having a griplength based on the determined thickness of the stack-up assembly 310.

With regard to validation using the calibrated probe 552, as describedherein, it is operable to verify a diameter of the drilled hole 524,verify a countersink depth associated with the drilled hole 524, andmeasure a thickness of the assembly 310 proximate the hole 524. Othervalidation processes may include, based on measurements of torque andangle of rotation, a flushness and a protrusion of the fastener and/or afastener bulb diameter associated with the installed fastener.

As described herein, the embodiments are directed to a fastener 300where application of torque to the fastener 300 operates to completeinstallation of the fastener 300 through rotation of a bolt 322 of thefastener 300 until a frangible drive head 324 breaks away from aremainder of the bolt 322 due to an increase of the torque required torotate the bolt 322 which is further due to the bulb being drawn upagainst the backside 316 of the assembly such that the nut body 320 canno longer be drawn up the bolt 322.

The embodiments also lead to a method for verifying correct one-sidedfastener installation that includes rotating a bolt 322 of the one-sidedfastener 300 until a torque required to rotate the bolt 322 causes adrive head 324 of the bolt 322 to separate therefrom, receiving ameasurement of the torque at which the drive head 324 separated from thebolt 322, and comparing the torque measurement to a torque-angle curveor torque range associated with the fastener 300 to verify a correctinstallation of the fastener 300. Rotating a bolt of the one-sidedfastener causes a bulb 350 in a one piece nut body 320 associated withthe bolt 322 to be formed on a backside of an assembly stack-up.Further, a rotation of the bolt 322 from a point where rotation of thebolt 322 was initiated, to a point where the drive head 324 separatesfrom the bolt 322 can be measured so that the measured rotation, forexample, in degrees, can be compared to an expected rotation to furtherverify correct installation of the fastener 300. Such rotationmeasurement may also be considered an alternative verification ofcorrect fastener installation.

FIG. 12 is a torque angle plot 700 related to the installation of tenfasteners 300. As shown for nine of the fasteners 300, at about 2250degrees of rotation (slightly over six complete rotations), the torquevalue become exponential indicating that the bulb 350 has formed andthat the bolt 322 is difficult to turn, which as described herein leadsto the separation of the drive head 324 from the bolt 322. Throughmonitoring of the rotation and or torque, and comparing to test data orprior installation data such as a torque range it can be determined thata fastener is correctly installed. However, for a tenth fastener, theplot 710 indicates an increase in torque after less than 1000 degrees ofrotation. Such may be an indicator of incorrect installation and isindicative of, for example, improper formation of bulb 350, selection ofan incorrect or defective fastener 300, or an issue with the drilledhole.

FIG. 13 is a diagram of a data processing system that might beincorporated within the above described drill-fill system 510. In thisillustrative example, data processing system 300 includes communicationsfabric 302, which provides communications between processor unit 304,memory 306, persistent storage 308, communications unit 310,input/output (I/O) unit 312, and display 314. The data processing system300 may include, as is understood from a review of the embodimentsdescribed herein, a torque sensor 830 and a rotation angle sensor 840operatively placed for use in sensing the torque required to break off adrive head 324 and recording the number of rotations of a bolt 322 priorto the drive head 324 breaking off. Torque sensor 830 and rotation anglesensor 840 may communicate through the communications unit 810 as shownor may communicate directly with processor unit 804 in otherembodiments. It should be understood that data processing system 800 isbut one embodiment of a data processing system that might be utilized inthe described embodiments. Other architectures and configurations ofdata processing systems capable of receiving sensor data from torquesensor 830 and rotation angle sensor 840 are known.

Continuing, processor unit 804 serves to execute instructions forsoftware that may be loaded into memory 806. Processor unit 804 may be aset of one or more processors or may be a multi-processor core,depending on the particular implementation. Further, processor unit 804may be implemented using one or more heterogeneous processor systems inwhich a main processor is present with secondary processors on a singlechip. As another illustrative example, processor unit 804 may be asymmetric multi-processor system containing multiple processors of thesame type.

Memory 806 and persistent storage 808 are examples of storage devices. Astorage device is any piece of hardware that is capable of storinginformation either on a temporary basis and/or a permanent basis. Memory806, in these examples, may be, for example, without limitation, arandom access memory or any other suitable volatile or non-volatilestorage device. Persistent storage 808 may take various forms dependingon the particular implementation. For example, without limitation,persistent storage 808 may contain one or more components or devices.For example, persistent storage 808 may be a hard drive, a flash memory,a rewritable optical disk, a rewritable magnetic tape, or somecombination of the above. The media used by persistent storage 808 alsomay be removable. For example, without limitation, a removable harddrive may be used for persistent storage 808.

Communications unit 810, in these examples, provides for communicationswith other data processing systems or devices. In these examples,communications unit 810 is a network interface card. Communications unit810 may provide communications through the use of either or bothphysical and wireless communication links.

Input/output unit 812 allows for input and output of data with otherdevices that may be connected to data processing system 800. Forexample, without limitation, input/output unit 812 may provide aconnection for user input through a keyboard and mouse. Further,input/output unit 812 may send output to a printer. Display 814 providesa mechanism to display information to a user.

Instructions for the operating system and applications or programs arelocated on persistent storage 808. These instructions may be loaded intomemory 806 for execution by processor unit 804. The processes of thedifferent embodiments may be performed by processor unit 804 usingcomputer implemented instructions, which may be located in a memory,such as memory 806. These instructions are referred to as program code,computer usable program code, or computer readable program code that maybe read and executed by a processor in processor unit 804. The programcode in the different embodiments may be embodied on different physicalor tangible computer readable media, such as memory 806 or persistentstorage 808.

Program code 816 is located in a functional form on computer readablemedia 818 that is selectively removable and may be loaded onto ortransferred to data processing system 800 for execution by processorunit 804. Program code 816 and computer readable media 818 form computerprogram product 820 in these examples. In one example, computer readablemedia 818 may be in a tangible form, such as, for example, an optical ormagnetic disc that is inserted or placed into a drive or other devicethat is part of persistent storage 808 for transfer onto a storagedevice, such as a hard drive that is part of persistent storage 808. Ina tangible form, computer readable media 818 also may take the form of apersistent storage, such as a hard drive, a thumb drive, or a flashmemory that is connected to data processing system 800. The tangibleform of computer readable media 818 is also referred to as computerrecordable storage media. In some instances, computer readable media 818may not be removable.

Alternatively, program code 816 may be transferred to data processingsystem 800 from computer readable media 818 through a communicationslink to communications unit 810 and/or through a connection toinput/output unit 812. The communications link and/or the connection maybe physical or wireless in the illustrative examples. The computerreadable media also may take the form of non-tangible media, such ascommunications links or wireless transmissions containing the programcode.

In some illustrative embodiments, program code 816 may be downloadedover a network to persistent storage 808 from another device or dataprocessing system for use within data processing system 800. Forinstance, program code stored in a computer readable storage medium in aserver data processing system may be downloaded over a network from theserver to data processing system 800. The data processing systemproviding program code 816 may be a server computer, a client computer,or some other device capable of storing and transmitting program code816.

The different components illustrated for data processing system 800 arenot meant to provide architectural limitations to the manner in whichdifferent embodiments may be implemented. The different illustrativeembodiments may be implemented in a data processing system includingcomponents in addition to or in place of those illustrated for dataprocessing system 800. Other components shown in FIG. 13 can be variedfrom the illustrative examples shown.

As one example, a storage device in data processing system 800 is anyhardware apparatus that may store data. Memory 806, persistent storage808 and computer readable media 818 are examples of storage devices in atangible form.

In another example, a bus system may be used to implement communicationsfabric 802 and may be comprised of one or more buses, such as a systembus or an input/output bus. Of course, the bus system may be implementedusing any suitable type of architecture that provides for a transfer ofdata between different components or devices attached to the bus system.Additionally, a communications unit may include one or more devices usedto transmit and receive data, such as a modem or a network adapter.Further, a memory may be, for example, without limitation, memory 806 ora cache such as that found in an interface and memory controller hubthat may be present in communications fabric 802.

This written description uses examples to disclose various embodiments,which include the best mode, to enable any person skilled in the art topractice those embodiments, including making and using any devices orsystems and performing any incorporated methods. The patentable scope isdefined by the claims, and may include other examples that occur tothose skilled in the art. Such other examples are intended to be withinthe scope of the claims if they have structural elements that do notdiffer from the literal language of the claims, or if they includeequivalent structural elements with insubstantial differences from theliteral languages of the claims.

1. A method for assembling a structure, said method comprising: locatinga position in an assembly stack-up where a one-sided fastener is to beinstalled; drilling a hole through the assembly stack-up at theposition; countersinking the hole to a specified depth; operating acalibrated probe to determine at least parameter associated with one ormore of the hole and the stack-up proximate the hole; inserting theone-sided fastener into the hole; applying a rotational torque to theone-sided fastener to complete installation of the one-sided fastener;and comparing a measurement of angular displacement required to completeinstallation of the one-sided fastener to a range of angulardisplacement indicative of correct installation of the fastener.
 2. Themethod of claim 1 further comprising comparing a measurement of thetorque required to complete the installation of the one-sided fastenerto a monitored torque-angle curve.
 3. The method of claim 1 whereincomparing a measurement of angular displacement required to completeinstallation comprises measuring an amount of angular displacementrequired to fracture a core bolt during installation to verify a correctinstallation of the fastener.
 4. The method of claim 1 wherein locatinga position in an assembly stack-up comprises: locating a reference onthe assembly stack-up; and location the position for the one-sidedfastener installation with respect to the reference location.
 5. Themethod of claim 1 wherein inserting the one-sided fastener into the holecomprises selecting a one-sided fastener having a grip length based onthe determined thickness of the stack-up.
 6. The method of claim 1wherein operating a calibrated probe further comprises at least one ofverifying a diameter of the drilled hole and verifying a countersinkdepth associated with the drilled hole.
 7. The method of claim 1 furthercomprising validating a flushness, a protrusion, and a fastener bulbdiameter associated with the installed fastener.
 8. The method of claim1 wherein applying a torque to the one-sided fastener to completeinstallation of the one-sided fastener comprises rotating a bolt of thefastener until a frangible drive head breaks away from a remainder ofthe bolt.
 9. A method for verifying correct one-sided fastenerinstallation, said method comprising: rotating a bolt of the one-sidedfastener until a torque required to rotate the bolt causes a drive headof the bolt to separate from the bolt; measuring a rotation of the boltfrom a point where rotation of the bolt was initiated, to a point wherethe drive head separates from the bolt; and comparing the measuredrotation to an expected rotation verify a correct installation of thefastener.
 10. The method according to claim 9 wherein rotating a bolt ofthe one-sided fastener comprises forming a bulb in a one piece nut bodyassociated with the bolt, the bulb formed on a backside of an assemblystack-up.
 11. The method according to claim 9 further comprising:receiving a measurement of the torque at which the drive head separatedfrom the bolt; and comparing the torque measurement to a torque rangecurve associated with the fastener.
 12. The method according to claim 9where the rotation of the drive head of the bolt is measured in degrees.13. A fastener insertion system comprising: a processing device; androtation angle sensor communicatively coupled to said processing device,said system operable to rotate a bolt of a one-sided fastener until atorque required to rotate the bolt causes a drive head of the bolt toseparate from the bolt, said processing device programmed to: receivemeasurements of the rotation of the bolt by said system; determine anangle of rotation at which the drive head separated from the bolt; andcompare the angle of rotation at which the drive head separated from thebolt to known values associated with the fastener.
 14. The fastenersystem according to claim 13 further comprising a torque sensorcommunicatively coupled to said processing device, said processingdevice programmed to: receive measurements of the torque utilized bysaid system to rotate the bolt; determine a torque at which the drivehead separated from the bolt; and compare the torque measurement atwhich the drive head separated from the bolt to known values associatedwith the fastener.
 15. The fastener system according to claim 14 whereinsaid processing device is programmed to compare the torque measurementand angle of rotation at which the drive head separated from the bolt toa torque rotation curve stored in a memory to determine if the fastenerwas installed correctly.
 16. The fastener system according to claim 15wherein the torque rotation curve is generated from at least one offastener installation test data and torque angle data generated fromprior fastener installations.